The Most Accurate Description of the Construction of a CDNA

The most accurate description of the construction of a cDNA library would be

A) collect all mRNA from tissue of interest, use reverse transcriptase to make cDNA, insert cDNA into plasmid vector.
B) extract all RNA from a sample, use Taq polymerase to make cDNA, sequence the cDNA.
C) isolate all rRNA, use DNA ligase to connect all the RNA together to make cDNA, transform the cDNA into bacteria.
D) filter all DNA from an organism and use Taq polymerase to make cDNA as a copy for the library, put cDNA into a viral vector.